1. Field of the Invention
This invention relates to the removal of water from roofs by gutter-downspout systems in general and to the alleviation of the problem of clogging of the gutter-downspout union by leaves, twigs and other debris in particular.
2. Prior Art
Two common methods for removing water runoff, generally rain, from a roof are the scupper and the gutter-downspout. Runoff should not be considered "guttered" until it leaves the roof. Up to that point it may or may not be channeled depending on the roof shape. A gutter channels the runoff to the mouth of the downspout. A scupper is not a gutter or part of the guttering component, but is generally a hole located in the facade of the top of the building which allows passage of runoff from the roof. An "open" scupper has two sides and a bottom spout-like component, forming what can be likened to a "U"-shaped channel through the building's facade. A "closed" scupper also includes a top or roof portion, thus defining a tunnel-like opening in the building's facade. An open scupper is less likely to become clogged, not having the top or roof on which debris can catch. Generally, a scupper channels the runoff to the "conductor" on the top edge of a downspout, but may just allow the runoff to fall directly to the ground.
The scupper-conductor method is not now, nor is likely to become, in widespread use because it only can be used where the roof or roof/facade is built in such a way as to channel the runoff to scuppers. Holding back the runoff while it is being channeled can add load to the roof structure and can encourage leaks and a shortened roof life. Additionally, if the scuppers were to become clogged, even only partially, the resulting backup of runoff could collapse the roof.
The common gutter-downspout system generally consists of a gutter horizontally attached to the building's facade and a downspout vertically attached to the building. The downspout is connected to the gutter via a hole cut in the bottom of the gutter trough which allows the roof runoff water contained in the gutter to leave the gutter by traveling vertically down the downspout to the ground. Various accessories can be attached to the gutter-downspout system, including "elbows" or bends in the downspout to alter the flow direction of the runoff in the downspout and splash blocks to lessen ground erosion where the runoff leaves the lower end of the downspout and contacts the ground.
In the gutter-downspout system, the runoff is discharged directly from the roof to the gutter. In the scupper-conductor system, the runoff is channeled along the inside surface of the building's facade to the scuppers. The gutter-downspout system uses a horizontal flow path for the runoff by means of a gutter which is commonly up to 50 feet long and sometimes longer. The scupper-conductor system uses a vertical flow path (free fall) for the runoff by means of a conductor which is usually only 12 inches to 14 inches high. As a result of the free fall and impact the flow becomes highly turbulent. Because of the scuppers and the turbulence, the scupper-conductor system is poor at removing debris, especially pine straw and small twigs.
The weakest links in the scupper-conductor and the gutter-downspout systems with regard to the removal of debris entrained in the runoff are the interfaces between the scupper and the conductor and the gutter and the downspout. Debris, such as leaves, twigs, and pine needles, is carried off of the roof and into the gutter or scupper with the runoff. Assuming the debris does not get caught or trapped in the gutter or scupper itself, the debris will be carried to the downspout or conductor along with the runoff. In the gutter-downspout system, there generally is a ninety degree (90.degree.) connection between the gutter and the downspout and the hole in the lower trough surface of the gutter leading to the downspout generally is about three inches (3") square. This configuration is susceptible to "bridging" by the debris across the opening in the gutter to the downspout and subsequent clogging of the downspout, thus reducing or blocking the flow of the runoff through the downspout.